1. cmScMeasCalcVal(): changed method of calculating the first and last
MIDI event in p->midiBuf[] and first and the score location window area
defined by 'bli' and 'ln'.

2. cmScMeasExec(): Set p->vsi and p->vsli to indicate that no new 'sets'
are available prior to the early return when locIdx==cmInvalidIdx.

measurements from a time-line file.

because it is now used as the 'bump' mode coefficient more often than it's original
intent as a threshold offset in the spec. dist. envelope following modes.

This would might be better accomplished inside cmProc4.c:cmScMeaExec().

so that it can correctly release the handle if the file read/parse fails.

Use _cmMpRtPtr to notice the first use of _cmMpRoot.